Re: deep copy of hash of hash

my $y = {%x};

Although this does create a reference to a new anonymous hash and copies the key/value pairs (you can modify the keys of %$y without affecting the set of keys in %x), this is still not a deep copy - the values are still references to the same nested hashes ({'lastname' => 'michael','tel'=>'222'}) as in the original data structure.

For true deep copies, see e.g. dclone from Storable or Clone.

Minor improvements to wording.

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Re^2: deep copy of hash of hash by cmic (Acolyte) on May 27, 2019 at 09:25 UTC
I get it. However, I loaded CPAN Clone module, but as I `use Clone 'Clone'; #or even: use Clone::More qw( clone );` [download] Perl -c answers: "Clone" is not exported by the Clone module What should I do? (sorry to be a bit noob there...) TYA -- cmic. Life helps. Perl Too.	[reply] [d/l]
Re^3: deep copy of hash of hash by hippo (Bishop) on May 27, 2019 at 10:07 UTC
Perl is case sensitive. Here is an SSCCE: `use strict; use warnings; use Test::More tests => 2; use Clone 'clone'; my %x = ( miller => {lastname => 'michael', tel => '222'}, duran => {lastname => 'peggy', tel => '333'}, ); my %y = %{clone (\%x)}; is_deeply (\%x, \%y); $x{duran}{tel} = '444'; isnt ($x{duran}{tel}, $y{duran}{tel});` [download]	[reply] [d/l]
Re^3: deep copy of hash of hash by johngg (Canon) on May 27, 2019 at 09:34 UTC
The documentation says `Use Clone 'clone';` (note the lower case) but you have asked to import `Clone` with an initial upper case letter. I can't test as I don't have that module but perhaps that is your problem. Cheers, JohnGG	[reply] [d/l] [select]


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